Well, you could do multiple formulas. Assuming Date in A1, and time in B1.
This date and time would be manually entered, obviously, and the formulas in
A2 and B2 are listed below (and copy down as needed).

The time formula would be modified as follows:
A2: =IF(B1+TIME(3,0,0)1,A1+1,A1)
B2: =IF(B1+TIME(3,0,0)1,B1+TIME(3,0,0)-1,B1+TIME(3,0,0))

Hope this helps.
--
John C


"Learner" wrote:

Does the DATE and TIME have to be in one cell; as I currently have these in
different columns?
--
Your help is appreciated
K


"Mike H" wrote:

Hi,

If you have a properly formatted date/ time in A1 this adds 3 hours to it

=A1+TIME(3,0,0)

So 1/1/2008 22:30 becomes 2/1/2008 01:30.

Mike

"Learner" wrote:

Apologies up front for not knowing excel terminology! I am a self-taught
excel user and have created a table with formulas which I now need to fine
tune, but don't know how. (Not even sure exactly what it's called that i've
created)
I am in the medical field and rely on certain blood tests being done at
certain times after a specific timepoint. I have created a table that when
specific data is entered; an automatic calculation occurs which tells you the
next dates and times certain blood tests are required for the duration of the
study. That was the easy part. My problem now is that if that dpecific
timepoint is say 01/01/2008 at 22:30 - I need my table to calculate what the
time would be 3; 6; 9; 12 hours later which i can get it to do; but the date
would also need to change to allow for the time going past midnight. How do I
do that?
--
Your help is appreciated
K